#include <stdio.h>

int main(int argc, char** argv)
{
 int a = 50;
 int b = 20;

 int* p = &a;
 int** p2 = &p;
 int*** p3 = &p2;

 *p2 = &b;
 **p2 = 30;

 printf("%i", b);

    return 0;
}